The Experts below are selected from a list of 2478 Experts worldwide ranked by ideXlab platform
Amir Sharon - One of the best experts on this subject based on the ideXlab platform.
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cAMP regulation of "pathogenic" and "saprophytic" Fungal Spore Germination.
Fungal genetics and biology : FG & B, 2004Co-Authors: Sima Barhoom, Amir SharonAbstract:We report on the elucidation of two separate pathways of Spore Germination in a plant pathogenic fungus Colletotrichum gloeosporioides f. sp. aeschynomene. Conidia of the fungus can germinate either from one side or from both sides, depending on external conditions. In shake culture that includes an extract made up from fresh peas, the unicellular conidium divides and one of the two cells develops a germ tube. On a solid surface this germ tube differentiates an appressorium. In rich medium without pea extract, Germination is highly similar to Aspergillus Spore Germination: the conidium swells, forms a single germ tube and then divides and forms a second germ tube. Conidia that germinate in a rich medium do not form appressoria even on a solid surface and are non-pathogenic. In rich medium, cAMP stimulates Germination in rich liquid cultures and induces appressoria formation on a hard surface. In pea extract cAMP induces swelling and formation of irregular germ tubes and appressoria. Our results suggest that plant surface signals induce pathogenic-specific Spore Germination in a cAMP-independent manner. cAMP is required for saprophytic Germination and for appressorium formation.
Mahammad Mehdi Yaghoobi - One of the best experts on this subject based on the ideXlab platform.
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Biological control of plant Fungal diseases using volatile substances of Streptomyces griseus
European Journal of Experimental Biology, 2014Co-Authors: Marzieh Danaei, Amin Baghizadeh, Shahram Pourseyedi, Javid Amini, Mahammad Mehdi YaghoobiAbstract:Streptomyces griseus is a useful bacteria that produces many secondary metabolites and volatile compounds. In this project, antiFungal activity of volatile substances derived from Streptomyces griseus against Penicillium chrysogenum and Botrytis cinerea was studied in vitro. The compositions of volatiles were also determined by gas chromatography comb with mass spectrometry analysis. Fungal Spore Germination and mycelium growth of both P.chrysogenum and B.cinerea cultures were significantly suppressed in the presence of the volatiles. Gas chromatography comb with mass spectrometry analysis results showed that twenty volatile compounds were identified in one week old diphasic cultures (Tryptic Soy Agar and Tryptic Soy Broth) of S.griseus. The volatile compounds were chemically grouped into organic acids, alcohol, alkanes, alkenes, alkens and ketones. The most abundant compounds in volatile of S.griseus were Phenol,2-methyl-5-1methylethyl(Carvacrol). Chemicals of less abundant were Isocyclocitral, Benzene,1,2-dimethoxy -4-1-methylethenyl. The antiFungal activity of S.griseus cultures can be attributed to Carvacrol, Dimethyl sulfoxide (DMSO), Cyclohexanol, Naphthalene. The volatile substances of S.griseus have a potential for using as a biofumigant to control plant Fungal diseases.
James F. A. Traniello - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of Fungal Spore Germination by Nasutitermes: Evidence for a Possible Antiseptic Role of Soldier Defensive Secretions
Journal of Chemical Ecology, 2000Co-Authors: Rebeca B. Rosengaus, Michele L. Lefebvre, James F. A. TranielloAbstract:The antiFungal property of two of the principal components of the terpenoid frontal gland secretions of nasute termite soldiers was studied by incubating Spore suspensions of the fungus Metarhizium anisopliae with α-pinene and limonene singly or in combination at different concentrations. In vitro assays showed that these substances reduced Spore Germination through direct and indirect (vapor) contact. To determine if the frontal gland secretions protected termites from Fungal infection in vivo, the effect of M. anisopliae on the time course of survival of Nasutitermes costalis and N. nigriceps was studied by exposing termites to either a 4.3 × 10^7 Spores/ml or a control Sporeless suspension. The caste composition of experimental groups was manipulated to create mixed-caste subcolonies and monocaste groups. Relative to Coptotermes formosanus , a species that relies on the mechanical defenses of soldiers, N. costalis and N. nigriceps were less susceptible to Fungal infection. Spore-exposed N. costalis and N. nigriceps termites had 1.2 times the hazard ratio of death of controls, while the hazard ratio of death of Spore-exposed C. formosanus was 11.4 times that of controls. Although the lower susceptibility to infection in Nasutitermes may be explained in part by the antiFungal properties of α-pinene and limonene, group composition also played a major role in the survival of Spore-exposed termites. Mixed-caste and soldier monocaste groups had 3.4 and 4.7 times the hazard ratio of death, respectively, relative to the worker monocaste treatment. These results suggest that although Nasutitermes terpenoid secretions may have antiFungal properties, the caste composition of groups and the social interactions of termites also play a role in determining susceptibility to Fungal infection.
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Inhibitory Effect of Termite Fecal Pellets on Fungal Spore Germination
Journal of Chemical Ecology, 1998Co-Authors: Rebeca B. Rosengaus, Matthew R. Guldin, James F. A. TranielloAbstract:The dampwood termite Zootermopsis angusticollis lines nest chambers and galleries with fecal pellets. The antiFungal properties of feces were tested by recording Germination rates of Spores of the fungus Metarhizium anisopliae that had been incubated with various concentrations of fecal material. The presence of fecal pellet material significantly decreased the Germination rates of Spores relative to those of control Spore solutions lacking fecal material. Spore Germination rates were inversely proportional to the amount of fecal matter present in the Spore–feces suspensions but were independent of incubation time. The fungistatic effect of the fecal material is virtually immediate and does not require prolonged contact with Spores to inhibit Germination. This mechanism of biochemical protection may reduce risks of Fungal infection in termite nests.
Nick D. Read - One of the best experts on this subject based on the ideXlab platform.
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live cell imaging of endocytosis during conidial Germination in the rice blast fungus magnaporthe grisea
Fungal Genetics and Biology, 2002Co-Authors: Helen A Atkinson, Alison Daniels, Nick D. ReadAbstract:Although there is growing evidence that endocytosis is important in hyphal tip growth, it has not previously been shown to occur during Fungal Spore Germination. We have analysed and characterized endocytosis during the Germination of living conidia of the rice blast fungus, Magnaporthe grisea. Conidia treated with the endocytic markers Lucifer Yellow carbohydrazide, FITC-dextran, and FM4-64 were imaged by confocal microscopy. Internalization of these fluorescent marker dyes by conidia was blocked by chemical and temperature treatments that inhibit endocytosis, and the sequential staining of organelles by the membrane-selective dye FM4-64 was consistent with dye internalization by endocytosis. FM4-64 uptake occurred within 2-3 min of conidial hydration, more than 40 min before the emergence of the germ tube. The times at which each of the three conidial cells initiated dye internalization were different as were the rates of dye uptake by each cell. Using these techniques we have demonstrated for the first time that ungerminated and germinated Spores of filamentous fungi undergo endocytosis. Furthermore, internalization of FITC-dextran and Lucifer Yellow carbohydrazide by germinating conidia provides the first direct evidence for fluid-phase endocytosis in a filamentous fungus. FM4-64 was internalized by both ungerminated conidia and conidial germlings on the rice leaf suggesting that endocytosis might play a significant role in Spore Germination and germ tube growth during the pre-penetration phase of infection.
Mukund V. Deshpande - One of the best experts on this subject based on the ideXlab platform.
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Fungal Spore Germination into yeast or mycelium: possible implications of dimorphism in evolution and human pathogenesis.
Die Naturwissenschaften, 2000Co-Authors: Vandana Ghormade, Mukund V. DeshpandeAbstract:The ability of dimorphism in fungi is conventionally regarded as a reversible change between the two vegetative forms, yeast and mycelium, in response to environmental change. A zygomycetous isolate, Benjaminiella poitrasii, exhibited yeast-mycelium transition in response to the change in temperature (37–28 °C) and decrease in glucose concentration. For the first time the presence of dimorphic response during asexual and sexual Spore Germination is reported under the dimorphism-triggering conditions in B. poitrasii. The zygoSpores germinated into budding yeast when subjected to yeast-form supporting conditions. The mycelium-form favoring conditions gave rise to true mycelium. Similarly, the asexual Spores displayed a dimorphic response during Germination. Our observations suggest that dimorphism is an intrinsic ability present in the vegetative, asexual, and sexual forms of the fungus. As dimorphic fungi are intermediate to the unicellular yeast and the filamentous forms, understanding of the dimorphic character could be useful to trace the evolutionary relationships among taxonomically different fungi. Moreover, the implications of Spore Germination during the onset of pathogenesis and in drug development for human health care are discussed.
